Average power tracking power management circuit

ABSTRACT

An average power tracking (APT) power management circuit is provided. The APT power management circuit is configured to generate a first APT voltage(s) for a first power amplifier(s) and a second APT voltage(s) for a second power amplifier(s). The APT power management circuit further includes a pair of switcher circuits that can generate a pair of reference voltages. Depending on various operating scenarios of the APT power management circuit, it is possible to selectively output any of the reference voltages as any one or more of the first APT voltage(s) and the second APT voltage(s). As such, it is possible to flexibly configure the APT power management circuit to support the various operating scenarios based on a minimum possible number of the switcher circuits, thus helping to reduce footprint and cost of the APT power management circuit.

RELATED APPLICATIONS

This application claims the benefit of provisional patent applicationSer. No. 63/037,282, filed Jun. 10, 2020, the disclosure of which ishereby incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

The technology of the disclosure relates generally to an average powertracking (APT) power management circuit.

BACKGROUND

Fifth-generation (5G) new radio (NR) (5G-NR) have been widely regardedas the next generation of wireless communication technology beyond thecurrent third-generation (3G) and fourth-generation (4G) technologies.In this regard, a wireless communication device capable of supportingthe 5G-NR wireless communication technology is expected to achievehigher data rate, improved coverage range, enhanced signalingefficiency, and reduced latency across a wide range of radio frequency(RF) bands, which include a low-band (below 1 GHz), a mid-band (1 GHz to6 GHz), and a high-band (above 24 GHz). Moreover, the wirelesscommunication device may still support the legacy 3G and 4G technologiesfor backward compatibility.

In addition, the wireless communication device is required to supportlocal area networking technologies, such as Wi-Fi, in both 2.4 GHz and 5GHz bands. The latest 802.11ax standard has introduced a dynamic powercontrol feature to allow the wireless communication device to transmit aWi-Fi signal with a maximum power ranging from −10 dBm to 23 dBm.Accordingly, a Wi-Fi power amplifier(s) in the wireless communicationdevice must be able to adapt the power level of the Wi-Fi signal on aper-frame basis. As a result, a power management integrated circuit(PMIC) must be able to adapt an average power tracking (APT) voltagesupplied to the Wi-Fi power amplifier(s) within Wi-Fi inter-framespacing (IFS) to help maintain linearity and efficiency of the Wi-Fipower amplifier(s).

Notably, the Wi-Fi IFS may only last sixteen microseconds (16 μs).Depending on specific configurations of the Wi-Fi system, such asbandwidth mode, trigger frame format, modulation and coding scheme(MCS), and delays associated with Wi-Fi physical layer (PHY) andcommunication buses, the actual temporal limit for the PMIC to adapt theAPT voltage(s) may be as short as one-half of a microsecond (0.5 μs). Inthis regard, it is desirable for the PMIC to adapt the APT voltage(s)from one level to another within a predetermined temporal limit (e.g.,0.5 μs).

SUMMARY

Embodiments of the disclosure relate to an average power tracking (APT)power management circuit. The APT power management circuit is configuredto generate a first APT voltage(s) for a first power amplifier(s) and asecond APT voltage(s) for a second power amplifier(s). The APT powermanagement circuit further includes a pair of switcher circuits that cangenerate a pair of reference voltages. Depending on various operatingscenarios of the APT power management circuit, it is possible toselectively output any of the reference voltages as any one or more ofthe first APT voltage(s) and the second APT voltage(s). As such, it ispossible to flexibly configure the APT power management circuit tosupport the various operating scenarios based on a minimum possiblenumber of the switcher circuits, thus helping to reduce footprint andcost of the APT power management circuit.

In one aspect, an APT power management circuit is provided. The APTpower management circuit includes a first switcher circuit configured togenerate a first reference voltage and induce a first low-frequencycurrent at a first reference node. The APT power management circuit alsoincludes a second switcher circuit configured to generate a secondreference voltage and induce a second low-frequency current at a secondreference node. The APT power management circuit also includes a numberof first hybrid circuits each coupled between the first reference nodeand a respective one of a number of first voltage outputs to output arespective one of a number of first APT voltages. The APT powermanagement circuit also includes a number of second hybrid circuits eachcoupled between the second reference node and a respective one of anumber of second voltage outputs to output a respective one of a numberof second APT voltages. The APT power management circuit also includes acontrol circuit. The control circuit is configured to cause at least oneof the plurality of first voltage outputs to output the first referencevoltage as the respective one of the plurality of first APT voltages.The control circuit is also configured to cause at least one of theplurality of second voltage outputs to output the second referencevoltage as the respective one of the plurality of second APT voltages.

In another aspect, an APT apparatus is provided. The APT apparatusincludes an APT power management circuit. The APT power managementcircuit includes a first switcher circuit configured to generate a firstreference voltage and induce a first low-frequency current at a firstreference node. The APT power management circuit also includes a secondswitcher circuit configured to generate a second reference voltage andinduce a second low-frequency current at a second reference node. TheAPT power management circuit also includes a number of first hybridcircuits each coupled between the first reference node and a respectiveone of a number of first voltage outputs to output a respective one of anumber of first APT voltages.

The APT power management circuit also includes a number of second hybridcircuits each coupled between the second reference node and a respectiveone of a number of second voltage outputs to output a respective one ofa number of second APT voltages. The APT power management circuit alsoincludes a control circuit. The control circuit is configured to causeat least one of the plurality of first voltage outputs to output thefirst reference voltage as the respective one of the plurality of firstAPT voltages. The control circuit is also configured to cause at leastone of the plurality of second voltage outputs to output the secondreference voltage as the respective one of the plurality of second APTvoltages.

Those skilled in the art will appreciate the scope of the presentdisclosure and realize additional aspects thereof after reading thefollowing detailed description of the preferred embodiments inassociation with the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The accompanying drawing figures incorporated in and forming a part ofthis specification illustrate several aspects of the disclosure, andtogether with the description serve to explain the principles of thedisclosure.

FIG. 1 is a schematic diagram of an exemplary average power tracking(APT) power management circuit configured according to an embodiment ofthe present disclosure; and

FIG. 2 is a schematic diagram of an exemplary APT power managementcircuit configured according to another embodiment of the presentdisclosure.

DETAILED DESCRIPTION

The embodiments set forth below represent the necessary information toenable those skilled in the art to practice the embodiments andillustrate the best mode of practicing the embodiments. Upon reading thefollowing description in light of the accompanying drawing figures,those skilled in the art will understand the concepts of the disclosureand will recognize applications of these concepts not particularlyaddressed herein. It should be understood that these concepts andapplications fall within the scope of the disclosure and theaccompanying claims.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element such as a layer, region, orsubstrate is referred to as being “on” or extending “onto” anotherelement, it can be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there are no intervening elements present.Likewise, it will be understood that when an element such as a layer,region, or substrate is referred to as being “over” or extending “over”another element, it can be directly over or extend directly over theother element or intervening elements may also be present. In contrast,when an element is referred to as being “directly over” or extending“directly over” another element, there are no intervening elementspresent. It will also be understood that when an element is referred toas being “connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present.

Relative terms such as “below” or “above” or “upper” or “lower” or“horizontal” or “vertical” may be used herein to describe a relationshipof one element, layer, or region to another element, layer, or region asillustrated in the Figures. It will be understood that these terms andthose discussed above are intended to encompass different orientationsof the device in addition to the orientation depicted in the Figures.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes,” and/or “including” when used herein specifythe presence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms used herein should be interpreted ashaving a meaning that is consistent with their meaning in the context ofthis specification and the relevant art and will not be interpreted inan idealized or overly formal sense unless expressly so defined herein.

Embodiments of the disclosure relate to an average power tracking (APT)power management circuit. The APT power management circuit is configuredto generate a first APT voltage(s) for a first power amplifier(s) and asecond APT voltage(s) for a second power amplifier(s). The APT powermanagement circuit further includes a pair of switcher circuits that cangenerate a pair of reference voltages. Depending on various operatingscenarios of the APT power management circuit, it is possible toselectively output any of the reference voltages as any one or more ofthe first APT voltage(s) and the second APT voltage(s). As such, it ispossible to flexibly configure the APT power management circuit tosupport the various operating scenarios based on a minimum possiblenumber of the switcher circuits, thus helping to reduce footprint andcost of the APT power management circuit.

In this regard, FIG. 1 is a schematic diagram of an exemplary APT powermanagement circuit 10 configured according to an embodiment of thepresent disclosure to adapt one or more of a pair of first APT voltagesV_(CCA), V_(CCB) and a pair of second APT voltages V_(CCC), V_(CCD) fromone level to another within a predetermined temporal limit.

The APT power management circuit 10 includes a first switcher circuit12A and a second switcher circuit 12B. Notably, the first switchercircuit 12A and the second switcher circuit 12B are merely non-limitingexamples. It should be appreciated that the APT power management circuit10 can be configured to include additional switcher circuits, ifdesired.

The first switcher circuit 12A is coupled to a first reference node 14Aand configured to generate a first reference voltage V_(REFA) (e.g., aconstant voltage) and induce a first low-frequency current I_(REFA)(e.g., a direct current) at the first reference node 14A. In anon-limiting example, the first switcher circuit 12A includes a firstmulti-level charge pump 16A (denoted as MCP) and a first power inductor18A. The first multi-level charge pump 16A is configured to generate thefirst reference voltage V_(REFA) at multiple levels based on a batteryvoltage V_(BAT). For example, the first multi-level charge pump 16A canoperate in a buck mode to generate the first reference voltage V_(REFA)at or below the battery voltage V_(BAT), or to operate in a boost modeto generate the first reference voltage V_(REFA) above the batteryvoltage V_(BAT). The first power inductor 18A is coupled between thefirst multi-level charge pump 16A and the first reference node 14A. Thefirst power inductor 18A is configured to induce the first low-frequencycurrent I_(REFA) based on the first reference voltage V_(REFA).

The second switcher circuit 12B is coupled to a second reference node14B and configured to generate a second reference voltage V_(REFB)(e.g., a constant voltage) and induce a second low-frequency currentI_(REFB) (e.g., a direct current) at the second reference node 14B. In anon-limiting example, the second switcher circuit 12B includes a secondmulti-level charge pump 16B (denoted as MCP) and a second power inductor18B. The second multi-level charge pump 16B is configured to generatethe second reference voltage V_(REFB) at multiple levels based on thebattery voltage V_(BAT). For example, the second multi-level charge pump16B can operate in the buck mode to generate the second referencevoltage V_(REFB) at or below the battery voltage V_(BAT), or to operatein the boost mode to generate the second reference voltage V_(REFB)above the battery voltage V_(BAT). The second power inductor 18B iscoupled between the second multi-level charge pump 16B and the secondreference node 14B. The second power inductor 18B is configured toinduce the second low-frequency current IREFB based on the secondreference voltage V_(REFB).

The APT power management circuit 10 includes a pair of first voltageoutputs 20A, 20B and a pair of second voltage outputs 20C, 20D. Thefirst voltage outputs 20A, 20B are configured to output the first APTvoltages V_(CCA), V_(CCB), respectively. The second voltage outputs 20C,20D are configured to output the second APT voltages V_(CCC), V_(CCD),respectively. It should be appreciated that the APT power managementcircuit 10 can include additional voltage outputs for outputtingadditional APT voltages, if desired.

The APT power management circuit 10 includes a control circuit 22, whichcan be a field-programmable gate array (FPGA), as an example. Thecontrol circuit 22 is configured to receive a pair of first APT targetvoltages V_(TGTA), V_(TGTB) corresponding to the first APT voltagesV_(CCA), V_(CCB), respectively. The control circuit 22 is configured toreceive a pair of second APT target voltages V_(TGTC), V_(TGTD)corresponding to the second APT voltages V_(CCC), V_(CCD), respectively.As discussed below, the control circuit 22 can selectively couple any ofthe first reference voltage V_(REFA) and the second reference voltageV_(REFB) to any one or more of the first voltage outputs 20A, 20B andthe second voltage outputs 20C, 20D based on the first APT targetvoltages V_(TGTA), V_(TGTB) and/or the second APT voltages V_(CCC),V_(CCD). As such, the APT power management circuit 10 can generate thefirst APT voltages V_(CCA), V_(CCB) and the second APT voltages V_(CCC),V_(CCD) in various operating scenarios based on the first switchercircuit 12A and the second switcher circuit 12B. As a result, it ispossible to reduce footprint and cost of the APT power managementcircuit 10.

The APT power management circuit 10 can be configured to include a pairof first hybrid circuits 24A, 24B and a pair of second hybrid circuits24C, 24D. The first hybrid circuits 24A, 24B are coupled between thefirst reference node 14A and the first voltage outputs 20A, 20B,respectively. The second hybrid circuits 24C, 24D are coupled betweenthe second reference node 14B and the second voltage outputs 20C, 20D,respectively. Understandably, the APT power management circuit 10 caninclude additional hybrid circuits if additional voltage outputs areadded to the APT power management circuit 10.

In a non-limiting example, each of the first hybrid circuits 24A, 24Band the second hybrid circuits 24C, 24D can include a transistor(s) thatcan be controlled via a respective bias voltage. As such, each of thefirst hybrid circuits 24A, 24B and the second hybrid circuits 24C, 24Dcan operate in a switch mode or in a regulator mode. When operating inthe switch mode, each of the first hybrid circuits 24A, 24B and thesecond hybrid circuits 24C, 24D functions as a switch to couple arespective one of the first reference voltage V_(REFA) and the secondreference voltage V_(REFB) and/or a respective one of the firstlow-frequency current I_(REFA) and the second low-frequency currentI_(REFB) directly to a respective one of the first voltage outputs 20A,20B and the second voltage outputs 20C, 20D. When operating in theregulator mode, each of the first hybrid circuits 24A, 24B and thesecond hybrid circuits 24C, 24D functions as a low dropout (LDO)regulator to regulate (e.g., reduce) a respective one of the firstreference voltage V_(REFA) and the second reference voltage V_(REFB)and/or a respective one of the first low-frequency current I_(REFA) andthe second low-frequency current I_(REFB) at a respective one of thefirst voltage outputs 20A, 20B and the second voltage outputs 20C, 20D.The control circuit 22 may cause each of the first hybrid circuits 24A,24B and the second hybrid circuits 24C, 24D to operate in the switchmode or the regulator mode via a respective one of a pair of firstcontrol signals 26A, 26B and a pair of second control signals 26C, 26D.

The control circuit 22 may be configured to cause at least one of thefirst hybrid circuits 24A, 24B and at least one of the second hybridcircuits 24C, 24D to operate in the switch mode. Accordingly, thecontrol circuit 22 can cause at least one of the first voltage outputs20A, 20B to output the first reference voltage V_(REFA) as a respectiveone of the first APT voltages V_(CCA), V_(CCB). Likewise, the controlcircuit 22 can also cause at least one of the second voltage outputs20C, 20D to output the second reference voltage V_(REFB) as a respectiveone of the second APT voltages V_(CCC), V_(CCD).

In one example, the control circuit 22 determine that a first one (e.g.,V_(TGTA)) of the first APT target voltages V_(TGTA), V_(TGTB) is higherthan a second one (e.g., V_(TGTB)) of the first APT target voltagesV_(TGTA), V_(TGTB) (V_(TGTA)>V_(TGTB)). In this regard, the controlcircuit 22 controls the first switcher circuit 12A to generate the firstreference voltage V_(REFA) based on the first one (e.g., V_(TGTA)) ofthe first APT target voltages V_(TGTA), V_(TGTB).

Accordingly, the control circuit 22 determines a first one (e.g., 24A)of the first hybrid circuits 24A, 24B coupled to a first one (e.g., 20A)of the first voltage outputs 20A, 20B that outputs a first one (e.g.,V_(CCA)) of the first APT voltages V_(CCA), V_(CCB) corresponding to thefirst one (e.g., V_(TGTA)) of the first APT target voltages V_(TGTA),V_(TGTB). The control circuit 22 then controls the first one (e.g., 24A)of the first hybrid circuits 24A, 24B to operate in the switch mode tooutput the first reference voltage V_(REFA) at the first one (e.g., 20A)of the first voltage outputs 20A, 20B.

Since the first reference voltage V_(REFA) is generated based on thehigher one (e.g., V_(TGTA)) of the first APT target voltages V_(TGTA),V_(TGTB), the first reference voltage V_(REFA) may be too high forgenerating a second one (e.g., V_(CCB)) of the first APT voltagesV_(CCA), V_(CCB). In this regard, the control circuit 22 furtherdetermines the second one (e.g., 24B) of the first hybrid circuits 24A,24B coupled to a second one (e.g., 20B) of the first voltage outputs20A, 20B that outputs the second one (e.g., V_(CCB)) of the first APTvoltages V_(CCA), V_(CCB) corresponding to the second one (e.g.,V_(TGTB)) of the first APT target voltages V_(TGTA), V_(TGTB).Accordingly, the control circuit 22 controls the second one (e.g., 24B)of the first hybrid circuits 24A, 24B to operate in the regulator modeto regulate (e.g., reduce) the first reference voltage V_(REFA) and/orthe first low-frequency current I_(REFA) at the second one (e.g., 20B)of the first voltage outputs 20A, 20B.

In another example, the control circuit 22 determine that a first one(e.g., V_(TGTA)) of the first APT target voltages V_(TGTA), V_(TGTB) isequal to a second one (e.g., V_(TGTB)) of the first APT target voltagesV_(TGTA), V_(TGTB) (V_(TGTA)=V_(TGTB)). In this regard, the controlcircuit 22 controls the first switcher circuit 12A to generate the firstreference voltage V_(REFA) based on any one of the first one (e.g.,V_(TGTA)) of the first APT target voltages V_(TGTA), V_(TGTB) and thesecond one (e.g., V_(TGTB)) of the first APT target voltages V_(TGTA),V_(TGTB). Accordingly, the control circuit 22 configures the firsthybrid circuits 24A, 24B to both operate in the switch mode to outputthe first reference voltage V_(REFA) to the first voltage outputs 20A,20B, respectively.

In another example, the control circuit 22 determine that a first one(e.g., V_(TGTC)) of the second APT target voltages V_(TGTC), V_(TGTD) ishigher than a second one (e.g., V_(TGTD)) of the second APT targetvoltages V_(TGTC), V_(TGTD) (V_(TGTC)>V_(TGTD)). In this regard, thecontrol circuit 22 controls the second switcher circuit 12B to generatethe second reference voltage V_(REFB) based on the first one (e.g.,V_(TGTC)) of the second APT target voltages V_(TGTC), V_(TGTD).

Accordingly, the control circuit 22 determines a first one (e.g., 24C)of the second hybrid circuits 24C, 24D coupled to a first one (e.g.,20C) of the second voltage outputs 20C, 20D that outputs a first one(e.g., V_(CCC)) of the second APT voltages V_(CCC), V_(CCD)corresponding to the first one (e.g., V_(TGTC)) of the second APT targetvoltages V_(TGTC), V_(TGTD). The control circuit 22 then controls thefirst one (e.g., 24C) of the second hybrid circuits 24C, 24D to operatein the switch mode to output the second reference voltage V_(REFB) atthe first one (e.g., 20C) of the second voltage outputs 20C, 20D.

Since the second reference voltage V_(REFB) is generated based on thehigher one (e.g., V_(TGTC)) of the second APT target voltages V_(TGTC),V_(TGTD), the second reference voltage V_(REFB) may be too high forgenerating a second one (e.g., V_(CCD)) of the second APT voltagesV_(CCC), V_(CCD). In this regard, the control circuit 22 furtherdetermines a second one (e.g., 24D) of the second hybrid circuits 24C,24D coupled to a second one (e.g., 20D) of the second voltage outputs20C, 20D that outputs the second one (e.g., V_(CCD)) of the second APTvoltages V_(CCC), V_(CCD) corresponding to the second one (e.g.,V_(TGTD)) of the second APT target voltages V_(TGTC), V_(TGTD).Accordingly, the control circuit 22 controls the second one (e.g., 24D)of the second hybrid circuits 24C, 24D to operate in the regulator modeto regulate (e.g., reduce) the second reference voltage V_(REFB) and/orthe second low-frequency current I_(REFB) at the second one (e.g., 20D)of the second voltage outputs 20C, 20D.

In another example, the control circuit 22 determine that a first one(e.g., V_(TGTC)) of the second APT target voltages V_(TGTC), V_(TGTD) isequal to a second one (e.g., V_(TGTD)) of the second APT target voltagesV_(TGTC), V_(TGTD) (V_(TGTC)=V_(TGTD)). In this regard, the controlcircuit 22 controls the second switcher circuit 12B to generate thesecond reference voltage V_(REFB) based on any one of the first one(e.g., V_(TGTC)) of the second APT target voltages V_(TGTC), V_(TGTD)and the second one (e.g., V_(TGTD)) of the second APT target voltagesV_(TGTC), V_(TGTD). Accordingly, the control circuit 22 configures thesecond hybrid circuits 24C, 24D to both operate in the switch mode tooutput the second reference voltage V_(REFB) to the second voltageoutputs 20C, 20D, respectively.

The APT power management circuit 10 can be provided in an APT apparatus28 that further includes a pair of first power amplifiers 30A, 30B and apair of second power amplifiers 30C, 30D. The first power amplifiers30A, 30B are coupled to the first voltage outputs 20A, 20B,respectively. Accordingly, first power amplifiers 30A, 30B areconfigured to amplify a pair of first radio frequency (RF) signals 32A,32B based on the first APT voltages V_(CCA), V_(CCB), respectively. In anon-limiting example, the first RF signals 32A, 32B can be Wi-Fi signalsto be transmitted in a 2.4 GHz band. The first RF signals 32A, 32B canbe identical or different.

The second power amplifiers 30C, 30D are coupled to the second voltageoutputs 20C, 20D, respectively. Accordingly, second power amplifiers30C, 30D are configured to amplify a pair of second RF signals 32C, 32Dbased on the second APT voltages V_(CCC), V_(CCD), respectively. In anon-limiting example, the second RF signals 32C, 32D can be Wi-Fisignals to be transmitted in a 5 GHz band. The second RF signals 32C,32D can be identical or different.

Notably, in the APT power management circuit 10, the first referencevoltage V_(REFA) can only be provided to one or more of the firstvoltage outputs 20A, 20B and the second reference voltage V_(REFB) canonly be provided to one or more of the second voltage outputs 20C, 20D.In certain operating scenarios, such configuration may cause some of thefirst hybrid circuits 24A, 24B and the second hybrid circuits 24C, 24Dto operate at suboptimal efficiency.

For example, if the first APT target voltages V_(TGTA), V_(TGTB) and thesecond APT target voltages V_(TGTC), V_(TGTD) are set at 5 V, 2 V, 2.5V, and 1 V, respectively, then the control circuit 22 will set the firstreference voltage V_(REFA) and the second reference voltage V_(REFB) at5 V (=V_(TGTA)) and 2.5 V (=V_(TGTC)), respectively. Accordingly, thefirst hybrid circuit 24A will operate in the switch mode to provide thefirst reference voltage V_(REFA) to the first voltage output 20A as thefirst APT voltage V_(CCA). In contrast, the first hybrid circuit 24Bneeds to operate in the regulator mode to reduce the first referencevoltage V_(REFA) from 5 V to 2 V (60% reduction) to thereby generate thefirst APT voltage V_(CCB). However, if the first hybrid circuit 24B caninstead generate the first APT voltage V_(CCB) based on the secondreference voltage V_(REFB), then the first hybrid circuit 24B only needsto reduce the second reference voltage V_(REFB) from 2.5 V to 2 V (20%reduction) to thereby generate the first APT voltage V_(CCB). As aresult, the first hybrid circuit 24B can operate with higher efficiencybased on the second reference voltage V_(REFB). Hence, it is desirableto flexibly provide any of the first reference voltage V_(REFA) and thesecond reference voltage V_(REFB) to any of the first voltage outputs20A, 20B and the second voltage outputs 20C, 20D.

In this regard, FIG. 2 is a schematic diagram of an exemplary APT powermanagement circuit 34 configured according to another embodiment of thepresent disclosure. Common elements between FIGS. 1 and 2 are showntherein with common element numbers and will not be re-described herein.

The APT power management circuit 34 further includes a coupling circuit36, which is coupled between the first reference node 14A and the secondreference node 14B. As such, the coupling circuit 36 can receive boththe first reference voltage V_(REFA) and the second reference voltageV_(REFB). Accordingly, the control circuit 22 can selectively couple thefirst reference voltage V_(REFA) to one or more of the second hybridcircuits 24C, 24D and/or selectively couple the second reference voltageV_(REFB) to one or more of the first hybrid circuits 24A, 24B. In anon-limiting example, the control circuit 22 can control the couplingcircuit 36 via a coupling control signal 38.

When operating in the regulator mode, each of the first hybrid circuits24A, 24B and the second hybrid circuits 24C, 24D may suffer anefficiency loss that can be approximated by an equation (Eq. 1) below.

Efficiency Loss=(V _(REF) −V _(CCX))*V _(CCX) /R _(LOADX)  (Eq. 1)

In the equation (Eq. 1), V_(REF) represents any one of the firstreference voltage V_(REFA) and the second reference voltage V_(REFB).V_(CCX) represents any of the first APT voltages V_(CCA), V_(CCB) andthe second APT voltages V_(CCC), V_(CCD). R_(LOADX) represents a loadimpedance seen at any of the first voltage outputs 20A, 20B and thesecond voltage outputs 20C, 20D. In this regard, for a constantV_(CCX)/R_(LOADX), the smaller a difference between V_(REF)−V_(CCX), thelower the efficiency loss may be. As discussed in the operating examplesbelow, the control circuit 22 can selectively couple any one of thefirst reference voltage V_(REFA) and the second reference voltageV_(REFB) to any of the first hybrid circuits 24A, 24B and the secondhybrid circuits 24C, 24D to help reduce efficiency loss in the regulatormode.

In one example, the control circuit 22 can determine that a first one(e.g., V_(TGTA)) of the first APT target voltages V_(TGTA), V_(TGTB) ishigher than a second one (e.g., V_(TGTB)) of the first APT targetvoltages V_(TGTA), V_(TGTB). Accordingly, the control circuit 22configures the first switcher circuit 12A to generate the firstreference voltage V_(REFA) to be greater than or equal to the first one(e.g., V_(TGTA)) of the first APT target voltages V_(TGTA), V_(TGTB). Inthe meantime, the control circuit 22 may determine that the secondreference voltage V_(REFB) is lower than the first one (e.g., V_(TGTA))of the first APT target voltages V_(TGTA), V_(TGTB), but is higher thanthe second one (e.g., V_(TGTB)) of the first APT target voltagesV_(TGTA), V_(TGTB) (V_(TGTA)>V_(REFB)>V_(TGTB)). Accordingly, thecontrol circuit 22 can control the coupling circuit 36 to couple thesecond reference voltage V_(REFB) to the second one (e.g., 24B) of thefirst hybrid circuits 24A, 24B. Since the second reference voltageV_(REFB) is higher than the second one (e.g., V_(TGTB)) of the first APTtarget voltages V_(TGTA), V_(TGTB), the control circuit 22 configuresthe second one (e.g., 24B) of the first hybrid circuits 24A, 24B tooperate in the regulator mode to regulate the second reference voltageV_(REFB).

In another example, the control circuit 22 can determine that a firstone (e.g., V_(TGTA)) of the first APT target voltages V_(TGTA), V_(TGTB)is higher than a second one (e.g., V_(TGTB)) of the first APT targetvoltages V_(TGTA), V_(TGTB). Accordingly, the control circuit 22configures the first switcher circuit 12A to generate the firstreference voltage V_(REFA) to be greater than or equal to the first one(e.g., V_(TGTA)) of the first APT target voltages V_(TGTA), V_(TGTB). Inthe meantime, the control circuit 22 may determine that the secondreference voltage V_(REFB) is lower than the first one (e.g., V_(TGTA))of the first APT target voltages V_(TGTA), V_(TGTB), but is equal to thesecond one (e.g., V_(TGTB)) of the first APT target voltages V_(TGTA),V_(TGTB)(V_(TGTA)>V_(REFB) =V_(TGTB)). Accordingly, the control circuit22 can control the coupling circuit 36 to couple the second referencevoltage V_(REFB) to the second one (e.g., 24B) of the first hybridcircuits 24A, 24B. Since the second reference voltage V_(REFB) is equalto the second one (e.g., V_(TGTB)) of the first APT target voltagesV_(TGTA), V_(TGTB), the control circuit 22 configures the second one(e.g., 24B) of the first hybrid circuits 24A, 24B to operate in theswitch mode to output the second reference voltage V_(REFB).

In another example, the control circuit 22 can determine that a firstone (e.g., V_(TGTC)) of second first APT target voltages V_(TGTC),V_(TGTD) is higher than a second one (e.g., V_(TGTD)) of the second APTtarget voltages V_(TGTC), V_(TGTD). Accordingly, the control circuit 22configures the second switcher circuit 12B to generate the secondreference voltage V_(REFB) to be greater than or equal to the first one(e.g., V_(TGTC)) of the second APT target voltages V_(TGTC), V_(TGTD).In the meantime, the control circuit 22 may determine that the firstreference voltage VREFC is lower than the first one (e.g., V_(TGTC)) ofthe second APT target voltages V_(TGTC), V_(TGTD), but is higher thanthe second one (e.g., V_(TGTD)) of the second APT target voltagesV_(TGTC), V_(TGTD) (V_(TGTB)>V_(REFA)>V_(TGTD)). Accordingly, thecontrol circuit 22 can control the coupling circuit 36 to couple thefirst reference voltage V_(REFA) to the second one (e.g., 24D) of thesecond hybrid circuits 24C, 24D. Since the first reference voltageV_(REFA) is higher than the second one (e.g., V_(TGTD)) of the secondAPT target voltages V_(TGTC), V_(TGTD), the control circuit 22configures the second one (e.g., 24D) of the second hybrid circuits 24C,24D to operate in the regulator mode to regulate the first referencevoltage V_(REFA).

In another example, the control circuit 22 can determine that a firstone (e.g., V_(TGTC)) of second first APT target voltages V_(TGTC),V_(TGTD) is higher than a second one (e.g., V_(TGTD)) of the second APTtarget voltages V_(TGTC), V_(TGTD). Accordingly, the control circuit 22configures the second switcher circuit 12B to generate the secondreference voltage V_(REFB) to be greater than or equal to the first one(e.g., V_(TGTC)) of the second APT target voltages V_(TGTC), V_(TGTD).In the meantime, the control circuit 22 may determine that the firstreference voltage V_(REFC) is lower than the first one (e.g., V_(TGTC))of the second APT target voltages V_(TGTC), V_(TGTD), but is equal tothe second one (e.g., V_(TGTD)) of the second APT target voltagesV_(TGTC), V_(TGTD) (V_(TGTB)>V_(REFA)=V_(TGTD)). Accordingly, thecontrol circuit 22 can control the coupling circuit 36 to couple thefirst reference voltage V_(REFA) to the second one (e.g., 24D) of thesecond hybrid circuits 24C, 24D. Since the first reference voltageV_(REFA) is equal to the second one (e.g., V_(TGTD)) of the second APTtarget voltages V_(TGTC), V_(TGTD), the control circuit 22 configuresthe second one (e.g., 24D) of the second hybrid circuits 24C, 24D tooperate in the switch mode to output the first reference voltageV_(REFA).

Those skilled in the art will recognize improvements and modificationsto the preferred embodiments of the present disclosure. All suchimprovements and modifications are considered within the scope of theconcepts disclosed herein and the claims that follow.

What is claimed is:
 1. An average power tracking (APT) power managementcircuit comprising: a first switcher circuit configured to generate afirst reference voltage and induce a first low-frequency current at afirst reference node; a second switcher circuit configured to generate asecond reference voltage and induce a second low-frequency current at asecond reference node; a plurality of first hybrid circuits each coupledbetween the first reference node and a respective one of a plurality offirst voltage outputs to output a respective one of a plurality of firstAPT voltages; a plurality of second hybrid circuits each coupled betweenthe second reference node and a respective one of a plurality of secondvoltage outputs to output a respective one of a plurality of second APTvoltages; and a control circuit configured to: cause at least one of theplurality of first voltage outputs to output the first reference voltageas the respective one of the plurality of first APT voltages; and causeat least one of the plurality of second voltage outputs to output thesecond reference voltage as the respective one of the plurality ofsecond APT voltages.
 2. The APT power management circuit of claim 1wherein: the first switcher circuit comprises a first multi-level chargepump configured to generate the first reference voltage based on abattery voltage to cause a first power inductor to induce the firstlow-frequency current; and the second switcher circuit comprises asecond multi-level charge pump configured to generate the secondreference voltage based on the battery voltage to cause a second powerinductor to induce the second low-frequency current.
 3. The APT powermanagement circuit of claim 2 wherein: the first power inductor iscoupled between the first multi-level charge pump and the firstreference node and configured to induce the first low-frequency currentbased on the first reference voltage; and the second power inductor iscoupled between the second multi-level charge pump and the secondreference node and configured to induce the second low-frequency currentbased on the second reference voltage.
 4. The APT power managementcircuit of claim 1 wherein: each of the plurality of first hybridcircuits is configured to: operate in a switch mode to couple the firstreference voltage and the first low-frequency current to the respectiveone of the plurality of first voltage outputs; and operate in aregulator mode to regulate the first reference voltage and the firstlow-frequency current provided to the respective one of the plurality offirst voltage outputs; and each of the plurality of second hybridcircuits is configured to: operate in the switch mode to couple thesecond reference voltage and the second low-frequency current to therespective one of the plurality of second voltage outputs; and operatein the regulator mode to regulate the second reference voltage and thesecond low-frequency current provided to the respective one of theplurality of second voltage outputs.
 5. The APT power management circuitof claim 4 wherein the control circuit is further configured to: receivea plurality of first APT target voltages corresponding to the pluralityof first APT voltages, respectively; determine that a first one of theplurality of first APT target voltages is higher than a second one ofthe plurality of first APT target voltages; determine a first one of theplurality of first hybrid circuits coupled to a first one of theplurality of first voltage outputs that outputs a first one of theplurality of first APT voltages corresponding to the first one of theplurality of first APT target voltages; and control the first one of theplurality of first hybrid circuits to operate in the switch mode tooutput the first reference voltage at the first one of the plurality offirst voltage outputs.
 6. The APT power management circuit of claim 5wherein the control circuit is further configured to control the firstswitcher circuit to generate the first reference voltage based on thefirst one of the plurality of first APT target voltages.
 7. The APTpower management circuit of claim 5 wherein the control circuit isfurther configured to: determine a second one of the plurality of firsthybrid circuits coupled to a second one of the plurality of firstvoltage outputs that outputs a second one of the plurality of first APTvoltages corresponding to the second one of the plurality of first APTtarget voltages; and control the second one of the plurality of firsthybrid circuits to operate in the regulator mode to regulate the firstreference voltage at the second one of the plurality of first voltageoutputs.
 8. The APT power management circuit of claim 4 wherein thecontrol circuit is further configured to: receive a plurality of secondAPT target voltages corresponding to the plurality of second APTvoltages, respectively; determine that a first one of the plurality ofsecond APT target voltages is higher than a second one of the pluralityof second APT target voltages; determine a first one of the plurality ofsecond hybrid circuits coupled to a first one of the plurality of secondvoltage outputs that outputs a first one of the plurality of second APTvoltages corresponding to the first one of the plurality of second APTvoltages; and control the first one of the plurality of second hybridcircuits to operate in the switch mode to output the first referencevoltage at the first one of the plurality of second voltage outputs. 9.The APT power management circuit of claim 8 wherein the control circuitis further configured to control the second switcher circuit to generatethe second reference voltage based on the first one of the plurality ofsecond APT target voltages.
 10. The APT power management circuit ofclaim 8 wherein the control circuit is further configured to: determinea second one of the plurality of second hybrid circuits coupled to asecond one of the plurality of second voltage outputs that outputs asecond one of the plurality of second APT voltages corresponding to thesecond one of the plurality of second APT voltages; and control thesecond one of the plurality of second hybrid circuits to operate in theregulator mode to regulate the first reference voltage at the second oneof the plurality of second voltage outputs.
 11. The APT power managementcircuit of claim 4 further comprising a coupling circuit coupled betweenthe first reference node and the second reference node, wherein thecontrol circuit is further configured to: selectively couple the firstreference voltage to one or more of the plurality of second hybridcircuits; and selectively couple the second reference voltage to one ormore of the plurality of first hybrid circuits.
 12. The APT powermanagement circuit of claim 11 wherein the control circuit is furtherconfigured to: receive a plurality of first APT target voltagescorresponding to the plurality of first APT voltages, respectively;determine that a first one of the plurality of first APT target voltagesis higher than a second one of the plurality of first APT targetvoltages; determine that the second reference voltage is lower than thefirst one of the plurality of first APT target voltages but higher thanthe second one of the plurality of first APT target voltages; determinea first one of the plurality of first hybrid circuits coupled to a firstone of the plurality of first voltage outputs that outputs a first oneof the plurality of first APT voltages corresponding to the first one ofthe plurality of first APT voltages; control the first one of theplurality of first hybrid circuits to operate in the switch mode tooutput the first reference voltage at the first one of the plurality offirst voltage outputs; determine a second one of the plurality of firsthybrid circuits coupled to a second one of the plurality of firstvoltage outputs that outputs a second one of the plurality of first APTvoltages corresponding to the second one of the plurality of first APTvoltages; couple the second reference voltage to the second one of theplurality of first hybrid circuits; and control the second one of theplurality of first hybrid circuits to operate in the regulator mode tooutput the second reference voltage at the second one of the pluralityof first voltage outputs.
 13. The APT power management circuit of claim11 wherein the control circuit is further configured to: receive aplurality of first APT target voltages corresponding to the plurality offirst APT voltages, respectively; determine that a first one of theplurality of first APT target voltages is higher than a second one ofthe plurality of first APT target voltages; determine that the secondreference voltage is lower than the first one of the plurality of firstAPT target voltages but equal to the second one of the plurality offirst APT target voltages; determine a first one of the plurality offirst hybrid circuits coupled to a first one of the plurality of firstvoltage outputs that outputs a first one of the plurality of first APTvoltages corresponding to the first one of the plurality of first APTvoltages; control the first one of the plurality of first hybridcircuits to operate in the switch mode to output the first referencevoltage at the first one of the plurality of first voltage outputs;determine a second one of the plurality of first hybrid circuits coupledto a second one of the plurality of first voltage outputs that outputs asecond one of the plurality of first APT voltages corresponding to thesecond one of the plurality of first APT voltages; couple the secondreference voltage to the second one of the plurality of first hybridcircuits; and control the second one of the plurality of first hybridcircuits to operate in the switch mode to output the second referencevoltage at the second one of the plurality of first voltage outputs. 14.The APT power management circuit of claim 11 wherein the control circuitis further configured to: receive a plurality of second APT targetvoltages corresponding to the plurality of second APT voltages,respectively; determine that a first one of the plurality of second APTtarget voltages is higher than a second one of the plurality of secondAPT target voltages; determine that the first reference voltage is lowerthan the first one of the plurality of second APT target voltages buthigher than the second one of the plurality of second APT targetvoltages; determine a first one of the plurality of second hybridcircuits coupled to a first one of the plurality of second voltageoutputs that outputs a first one of the plurality of second APT voltagescorresponding to the first one of the plurality of second APT voltages;control the first one of the plurality of second hybrid circuits tooperate in the switch mode to output the second reference voltage at thefirst one of the plurality of second voltage outputs; determine a secondone of the plurality of second hybrid circuits coupled to a second oneof the plurality of second voltage outputs that outputs a second one ofthe plurality of second APT voltages corresponding to the second one ofthe plurality of second APT voltages; couple the first reference voltageto the second one of the plurality of second hybrid circuits; andcontrol the second one of the plurality of second hybrid circuits tooperate in the regulator mode to output the first reference voltage atthe second one of the plurality of second voltage outputs.
 15. The APTpower management circuit of claim 11 wherein the control circuit isfurther configured to: receive a plurality of second APT target voltagescorresponding to the plurality of second APT voltages, respectively;determine that a first one of the plurality of second APT targetvoltages is higher than a second one of the plurality of second APTtarget voltages; determine that the first reference voltage is lowerthan the first one of the plurality of second APT target voltages buthigher than the second one of the plurality of second APT targetvoltages; determine a first one of the plurality of second hybridcircuits coupled to a first one of the plurality of second voltageoutputs that outputs a first one of the plurality of second APT voltagescorresponding to the first one of the plurality of second APT voltages;control the first one of the plurality of second hybrid circuits tooperate in the switch mode to output the second reference voltage at thefirst one of the plurality of second voltage outputs; determine a secondone of the plurality of second hybrid circuits coupled to a second oneof the plurality of second voltage outputs that outputs a second one ofthe plurality of second APT voltages corresponding to the second one ofthe plurality of second APT voltages; couple the first reference voltageto the second one of the plurality of second hybrid circuits; andcontrol the second one of the plurality of second hybrid circuits tooperate in the regulator mode to output the first reference voltage atthe second one of the plurality of second voltage outputs.
 16. Anaverage power tracking (APT) apparatus comprising: an APT powermanagement circuit comprising: a first switcher circuit configured togenerate a first reference voltage and induce a first low-frequencycurrent at a first reference node; a second switcher circuit configuredto generate a second reference voltage and induce a second low-frequencycurrent at a second reference node; a plurality of first hybrid circuitseach coupled between the first reference node and a respective one of aplurality of first voltage outputs to output a respective one of aplurality of first APT voltages; a plurality of second hybrid circuitseach coupled between the second reference node and a respective one of aplurality of second voltage outputs to output a respective one of aplurality of second APT voltages; and a control circuit configured to:cause at least one of the plurality of first voltage outputs to outputthe first reference voltage as the respective one of the plurality offirst APT voltages; and cause at least one of the plurality of secondvoltage outputs to output the second reference voltage as the respectiveone of the plurality of second APT voltages.
 17. The APT apparatus ofclaim 16 further comprising: a plurality of first power amplifiers eachcoupled to a respective one of the plurality of first voltage outputsand configured to amplify a respective one of a plurality of first radiofrequency (RF) signals based on a respective one of the plurality offirst APT voltages; and a plurality of second power amplifiers eachcoupled to a respective one of the plurality of second voltage outputsand configured to amplify a respective one of a plurality of second RFsignals based on a respective one of the plurality of second APTvoltages.
 18. The APT apparatus of claim 16 wherein: the first switchercircuit comprises a first multi-level charge pump configured to generatethe first reference voltage based on a battery voltage to cause a firstpower inductor to induce the first low-frequency current; and the secondswitcher circuit comprises a second multi-level charge pump configuredto generate the second reference voltage based on the battery voltage tocause a second power inductor to induce the second low-frequencycurrent.
 19. The APT apparatus of claim 16 wherein: each of theplurality of first hybrid circuits is configured to: operate in a switchmode to couple the first reference voltage and the first low-frequencycurrent to the respective one of the plurality of first voltage outputs;and operate in a regulator mode to regulate the first reference voltageand the first low-frequency current provided to the respective one ofthe plurality of first voltage outputs; and each of the plurality ofsecond hybrid circuits is configured to: operate in the switch mode tocouple the second reference voltage and the second low-frequency currentto the respective one of the plurality of second voltage outputs; andoperate in the regulator mode to regulate the second reference voltageand the second low-frequency current provided to the respective one ofthe plurality of second voltage outputs.
 20. The APT apparatus of claim19 wherein the APT power management circuit further comprises a couplingcircuit coupled between the first reference node and the secondreference node, wherein the control circuit is further configured to:selectively couple the first reference voltage to one or more of theplurality of second hybrid circuits; and selectively couple the secondreference voltage to one or more of the plurality of first hybridcircuits.